An Update on Corneal Biomechanics and Architecture in Diabetes.

In the last decade, we have witnessed substantial progress in our understanding of corneal biomechanics and architecture. It is well known that diabetes is a systemic metabolic disease that causes chronic progressive damage in the main organs of the human body, including the eyeball. Although the main and most widely recognized ocular effect of diabetes is on the retina, the structure of the cornea (the outermost and transparent tissue of the eye) can also be affected by the poor glycemic control characterizing diabetes. The different corneal structures (epithelium, stroma, and endothelium) are affected by specific complications of diabetes. The development of new noninvasive diagnostic technologies has provided a better understanding of corneal tissue modifications. The objective of this review is to describe the advances in the knowledge of the corneal alterations that diabetes can induce.

CHOROIDAL THICKNESS AND VOLUME IN A HEALTHY PEDIATRIC POPULATION AND ITS RELATIONSHIP WITH AGE, AXIAL LENGTH, AMETROPIA, AND SEX.

PURPOSE: To evaluate choroidal thickness (CT) and volume in healthy pediatric individuals using enhanced depth imaging spectral domain optical coherence tomography (SD-OCT), as well as its association with age, sex, axial length (AL), and refractive error. METHODS: Ninety-three eyes from 93 healthy pediatric individuals were examined. An Early Treatment Diabetic Retinopathy Study grid was applied to analyze CT and volume map in each of its nine sectors. RESULTS: The mean subfoveal CT and volume were 314.22 ± 55.48 µm and 0.25 ± 0.04 mm, respectively. The nasal CT and volume of both the inner and the outer rings were significantly lower than the temporal area of the same ring and lower than the subfoveal choroidal thickness. A significant negative correlation between the subfoveal CT and AL (r = -0.250, P = 0.015) and a significant positive correlation between the subfoveal CT and refractive error (r = 0.238, P = 0.006) were found. The estimation of the variation in the subfoveal CT in relationship to the AL was -13.55 µm per millimeter. The variation in the subfoveal CT with refractive error was 7.52 µm per diopter. The estimation of the variation in the total choroidal volume related to the AL and ametropia was, respectively, -0.2354 mm per millimeter and 0.1412 mm per diopter. CONCLUSION: Healthy pediatric subjects exhibit choroidal differences in refractive error and AL. In the study population, CT and volume show an increase with age after adjusting for AL.